The present invention relates generally to optical switches. More particularly, the present invention relates to an optical switch comprising two fiber arrays facing each other. Relative lateral translation of the fiber arrays provides switching action.
Optical switches are used in optical data networks. Many varieties of optical switches have been invented, and different switches required for different applications. Switches are typically characterized by their switching speed, insertion loss, and connectivity (the number of connections that can be provided).
Optical computer networks will require inexpensive optical switches that are easy to manufacture and mechanically robust. Such switches may be mechanical in nature because they do not typically require high speed. Also, such switches should have a relatively high connectivity capability.
U.S. Pat. No. 5,623,564 to Presby teaches an optical switch having silica waveguide chips. The chips are facing each other so that the waveguides are butt-coupled. Switching action is provided by sliding the chips transversely with respect to one another. The device can provide low insertion loss.
U.S. Pat. No. 4,699,457 to Goodman teaches an optical fiber switch having fibers mounted on two blocks. One block can slide with respect to the other to provide switching action. The sliding motion is provided my a magnetic actuator.
U.S. Pat. No. 5,828,800 to Henry et al. teaches a sliding mechanical optical switch. The switch has two outer waveguide arrays and a central array that is movable. Switching action is provided by moving the central array.
U.S. Pat. No. 5,177,804 to Shimizu et al. teaches an optical switch having abutted fiber arrays which provide switching action when displaced laterally. The fiber arrays have slots for providing mechanical stops.
U.S. Pat. No. 4,150,870 to d""Auria teaches an optical fiber switch having bundles of fibers that can move laterally to provide switching action.
U.S. Pat. No. 5,699,463 to Yang et al. teaches an optical fiber switch having laterally translatable fiber arrays. A lens is disposed between the fiber arrays to provide relaxed alignment requirements.
U.S. Pat. No. 5,187,758 to Ueda et al. teaches an optical fiber switch having laterally translatable fiber arrays. The switch is made by cutting a single fiber array into two pieces. The fiber arrays have equal fiber spacing because they are made from the same V-groove chips.
U.S. Pat. No. 5,185,825 to Shigematsu et al. teaches an optical fiber switch having laterally translatable fiber arrays. The fiber arrays have slots for alignment pins that provide mechanical stops for switch positions.
U.S. Pat. No. 5,555,333 to Kato teaches an optical device for aligning an optical fiber array with optical components such as photodetectors. A photodetector chip has bumps for mechanically aligning with V-grooves in the optical fiber array.
U.S. Pat. No. 5,179,609 to Blonder et al. teaches an optical subassembly or connecting optical fibers and an optical device such as a photodetector. Optical fibers are disposed in V-grooves of a V-groove chip and the V-groove chip has pits on a front face for engaging mechanical features of a submount chip. The optical fibers are oriented perpendicularly with respect to the submount chip.
U.S. Pat. No. 5,778,123 to Hagan et al. teaches an optical fiber connector having alignment balls on the front surfaces of the connector. Fiber-fiber alignment is provided by mechanical contact between the connector and the alignment balls.
It would be an advance in the art of optical fiber switches to provide a mechanically robust switch with improved fiber-fiber alignment.
Accordingly, it is a primary object of the present invention to provide a mechanical optical fiber switch that:
1) is mechanically tough and robust;
2) is simple to assemble;
3) provides low insertion loss and is capable of high connectivity; and
4) provides good fiber-fiber mechanical alignment.
5) can be used with a wide variety of actuator devices.
These and other objects and advantages will be apparent upon reading the following description and accompanying drawings.
These objects and advantages are attained by an optical fiber switch having a first fiber array and a second fiber array. Each fiber array has a front face and an optical fiber terminating at the front face. Each fiber array also has a front face groove extending in a transverse direction. At least two spheres are disposed between the fiber arrays in the front face grooves so that the fiber arrays move in a transverse direction by rolling on the spheres. Transverse motion provides switching action by aligning and misaligning the optical fibers.
Preferably, the fiber arrays are made from anisotropically etched silicon chips. The front face grooves can be made by anisotropic etching.
Preferably, the spheres contact surfaces of the front face grooves, and not corners of the front face grooves.
Also preferably, the front face grooves and spheres are designed so that the optical fibers are spaced apart by a distance in the range of about 0.5-15 microns.
Also, the front faces of the fiber arrays can be angled to reduce backreflection.
The front face grooves can also have notches for providing passive transverse alignment.
The present invention includes an embodiment having a movable fiber array disposed between two stationary arrays. The movable array and stationary arrays have front face grooves and spheres are disposed in the grooves. The movable array moves in a transverse direction between the stationary arrays by rolling on the spheres.